1. Field of the Invention
A solar water heater of the type utilizing a collector unit having a primary heating structure disposed in fluid communication with a main collector plate disposed in exposed relation to the sun's rays.
2. Description of the Prior Art
Solar heating systems have long been known as a method of obtaining hot water or other fluids without the use of traditional fuels. Generally, such heating systems have been utilized for the purpose of attempting to stave heating costs by eliminating the need for such traditional fuels or at least reducing the actual quantity of usage. Numerous prior art systems have been utilized by the industry and are also now commercially available.
However, even though solar heating systems have been known and been in practice for some time, there are recognized inherent disadvantages found in these prior art systems. Many of these known devices are generally not self-contained and fluid flow through the entire system is primarily dependent upon line pressure of the fluid to force the fluid through the coils of the heat exchanger. Obvious problems arise when the line pressure is not sufficient to overcome the pressure forcing the fluid through the various tubing comprising the heat exchanger since tubing is generally of a restricted diameter of transverse dimension relative to conventional piping.
Perhaps the greatest problem associated with prior art or known solar heating systems is efficiency of operation or performance capabilities. This problem of inefficiency is generally blamed on a number of structural features of the prior art systems ranging from improper insulation to inefficient heat collecting plates, etc.
Generally, the basic structure of known solar heating systems includes some type of collector plate exposed to the direct rays of the sun wherein the collector plate comprises tubing through which the water or liquid to be heated flows. Theoretically, the sun's energy is absorbed into the coils in the form of heat and transferred to the liquid. The liquid is then stored in a storage tank of normal conventional design. A number of the existing systems further cause forced circulation to occur on a constant or periodic basis dependent upon the temperature of the water desired and the difference in this temperature from the water being maintained in any storage tank or facility. While functional, this type of arrangement does not always result in maximum operating efficiency.
Another problem commonly present in the prior art and recognized in the heating industry is the existence of temperature sensers which are forced to be located in direct contact with the fluid flow and which therefore impair the flow of fluid through the coils. Temperature sensors are also utilized in prior art devices as mechanical means to regulate the flow of fluid dependent upon the particular desired temperature or the range of temperatures intended for adequate operation of the system. In order to accomplish more efficient results, the temperature sensors frequently are designed to an overly complex state. Such relatively sophisticated sensors are designed to rely upon expansion of metals to accomplish control of fluid flow depending upon the temperature change of the fluid and accordingly, in the tubing through which the fluid is directed. In addition, problems frequently arise from the fluid being heated in the exchanger which contains chemicals which are deposited around the flow valve associated within the sensing apparatus causing the valve to become inoperable. Overall, the complexity of such prior art systems generally produces overly expensive devices which are costly to purchase and maintain and which have questionable operating characteristics.
It is recognized that an efficient functional and reliable solar heating system would be quite desirable in the heating industry.